Short Total Synthesis of (±)-Sceptrin

Gifted with novel chemical features and extraordinary biological activity, sceptrin has remained a prominent unanswered synthetic challenge since its characterization in 1981 by Faulkner and Clardy. A concise and practical solution to the myriad of chemical challenges posed by sceptrin is reported in this Communication. Thus, through a sequence involving rearrangement of an oxaquadricyclane, a new method for chemo- and regioselective halogenation, a mild sequence for 2-aminoimidazole formation, and careful synthetic choreography, (±)-sceptrin is obtained in a minimum of steps and in 24% overall yield from dimethyl acetylenedicarboxylate without a single use of chromatography.